这么晚了，但最终我得到了一些东西，我已经测试了大多数设备(通过制造商和android版本)，它在android 2.2+上工作。如果您发现它不起作用，请用您的设备名称注释它。我会解决的。如果有人感兴趣，我会解释它是如何工作的。

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FilenameFilter;
import java.io.IOException;
import java.io.InputStreamReader;

import android.util.Log;


/**
 * @author ajeet
 *05-Dec-2014  2014
 *
 */
public class StorageUtil {

    public boolean isRemovebleSDCardMounted() {
        File file = new File("/sys/class/block/");
        File[] files = file.listFiles(new MmcblkFilter("mmcblk\\d$"));
        boolean flag = false;
        for (File mmcfile : files) {
            File scrfile = new File(mmcfile, "device/scr");
            if (scrfile.exists()) {
                flag = true;
                break;
            }
        }
        return flag;
    }

    public String getRemovebleSDCardPath() throws IOException {
        String sdpath = null;
        File file = new File("/sys/class/block/");
        File[] files = file.listFiles(new MmcblkFilter("mmcblk\\d$"));
        String sdcardDevfile = null;
        for (File mmcfile : files) {
            Log.d("SDCARD", mmcfile.getAbsolutePath());
            File scrfile = new File(mmcfile, "device/scr");
            if (scrfile.exists()) {
                sdcardDevfile = mmcfile.getName();
                Log.d("SDCARD", mmcfile.getName());
                break;
            }
        }
        if (sdcardDevfile == null) {
            return null;
        }
        FileInputStream is;
        BufferedReader reader;

        files = file.listFiles(new MmcblkFilter(sdcardDevfile + "p\\d+"));
        String deviceName = null;
        if (files.length > 0) {
            Log.d("SDCARD", files[0].getAbsolutePath());
            File devfile = new File(files[0], "dev");
            if (devfile.exists()) {
                FileInputStream fis = new FileInputStream(devfile);
                reader = new BufferedReader(new InputStreamReader(fis));
                String line = reader.readLine();
                deviceName = line;
            }
            Log.d("SDCARD", "" + deviceName);
            if (deviceName == null) {
                return null;
            }
            Log.d("SDCARD", deviceName);

            final File mountFile = new File("/proc/self/mountinfo");

            if (mountFile.exists()) {
                is = new FileInputStream(mountFile);
                reader = new BufferedReader(new InputStreamReader(is));
                String line = null;
                while ((line = reader.readLine()) != null) {
                    // Log.d("SDCARD", line);
                    // line = reader.readLine();
                    // Log.d("SDCARD", line);
                    String[] mPonts = line.split("\\s+");
                    if (mPonts.length > 6) {
                        if (mPonts[2].trim().equalsIgnoreCase(deviceName)) {
                            if (mPonts[4].contains(".android_secure")
                                    || mPonts[4].contains("asec")) {
                                continue;
                            }
                            sdpath = mPonts[4];
                            Log.d("SDCARD", mPonts[4]);

                        }
                    }

                }
            }

        }

        return sdpath;
    }

    static class MmcblkFilter implements FilenameFilter {
        private String pattern;

        public MmcblkFilter(String pattern) {
            this.pattern = pattern;

        }

        @Override
        public boolean accept(File dir, String filename) {
            if (filename.matches(pattern)) {
                return true;
            }
            return false;
        }

    }

}

为了检索所有外部存储(无论是SD卡还是内部不可移动存储)，您可以使用以下代码:

final String state = Environment.getExternalStorageState();

if ( Environment.MEDIA_MOUNTED.equals(state) || Environment.MEDIA_MOUNTED_READ_ONLY.equals(state) ) {  // we can read the External Storage...           
    //Retrieve the primary External Storage:
    final File primaryExternalStorage = Environment.getExternalStorageDirectory();

    //Retrieve the External Storages root directory:
    final String externalStorageRootDir;
    if ( (externalStorageRootDir = primaryExternalStorage.getParent()) == null ) {  // no parent...
        Log.d(TAG, "External Storage: " + primaryExternalStorage + "\n");
    }
    else {
        final File externalStorageRoot = new File( externalStorageRootDir );
        final File[] files = externalStorageRoot.listFiles();

        for ( final File file : files ) {
            if ( file.isDirectory() && file.canRead() && (file.listFiles().length > 0) ) {  // it is a real directory (not a USB drive)...
                Log.d(TAG, "External Storage: " + file.getAbsolutePath() + "\n");
            }
        }
    }
}

或者，您可以使用System.getenv("EXTERNAL_STORAGE")来检索主要的外部存储目录(例如:"/storage/sdcard0")和System.getenv("SECONDARY_STORAGE")来检索所有从目录的列表(例如:“/存储/ extSdCard: /存储/ UsbDriveA: /存储/ UsbDriveB”)。记住，同样在这种情况下，您可能想要过滤从目录列表以排除USB驱动器。

在任何情况下，请注意使用硬编码路径总是一种糟糕的方法(特别是当每个制造商都可以随心所欲地更改它时)。

如果你看一下Android .os. environment的源代码，你会发现Android非常依赖环境变量作为路径。您可以使用“SECONDARY_STORAGE”环境变量来查找到可移动sd卡的路径。

/**
 * Get a file using an environmental variable.
 *
 * @param variableName
 *         The Environment variable name.
 * @param paths
 *         Any paths to the file if the Environment variable was not found.
 * @return the File or {@code null} if the File could not be located.
 */
private static File getDirectory(String variableName, String... paths) {
    String path = System.getenv(variableName);
    if (!TextUtils.isEmpty(path)) {
        if (path.contains(":")) {
            for (String _path : path.split(":")) {
                File file = new File(_path);
                if (file.exists()) {
                    return file;
                }
            }
        } else {
            File file = new File(path);
            if (file.exists()) {
                return file;
            }
        }
    }
    if (paths != null && paths.length > 0) {
        for (String _path : paths) {
            File file = new File(_path);
            if (file.exists()) {
                return file;
            }
        }
    }
    return null;
}

使用示例:

public static final File REMOVABLE_STORAGE = getDirectory("SECONDARY_STORAGE");

由于上面我最初的回答，扫描vold在各个制造商中不再可行。

我发明了一种更可靠更直接的方法。

File mnt = new File("/storage");
if (!mnt.exists())
    mnt = new File("/mnt");

File[] roots = mnt.listFiles(new FileFilter() {

    @Override
    public boolean accept(File pathname) {
        return pathname.isDirectory() && pathname.exists()
                && pathname.canWrite() && !pathname.isHidden()
                && !isSymlink(pathname);
    }
});

根目录将包含系统上所有可写的根目录，包括任何usb连接的usb设备。

注意:canWrite方法需要android.permission。WRITE_EXTERNAL_STORAGE许可。

通过编写下面的代码，您将获得位置:

数据存储663D-554E / Android / app_package_name / files /

存储你的应用程序数据在/android/数据位置内的sd_card。

File[] list = ContextCompat.getExternalFilesDirs(MainActivity.this, null);

list[1]+"/fol" 

对于获取位置，内部传递0,sdcard传递1到文件数组。

我已经在moto g4 plus和三星设备上测试了这段代码(一切正常)。

希望这对你有所帮助。

我不知道为什么，但我需要在使用它之前在公共存储目录中创建的文件上调用. createnewfile()。在框架中，该方法的注释说它没有用。这是一个样本……

String myPath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PODCASTS) + File. txt文件。separator +“我的目录”; final File myDir = new File(myypath); 尝试{ myDir.mkdirs (); } catch(异常ex) { 吐司。makeText(this， "error: " + ex.getMessage()， Toast.LENGTH_LONG).show(); ｝

        String fname = "whatever";
        File newFile = new File(myDir, fname);

        Log.i(TAG, "File exists --> " + newFile.exists()) //will be false  
    try {
            if (newFile.createNewFile()) {

                 //continue 

              } else {

                Log.e(TAG, "error creating file");

            }

        } catch (Exception e) {
            Log.e(TAG, e.toString());
        }